The present invention relates to portable battery powered personal computers such as laptop computers, and particularly to maximizing the charge on the battery, and consequently the period of time that the computer can be used on battery power.
Since their commercial introduction in the mid 1980""s, battery powered personal computers, particularly laptop computers, have sold in the hundreds of millions and have become an industry staple. The human factors, i.e. ease of use of such laptops, e.g. size, weight, clarity and size of display and response time have continually been improved to point that it appears as if virtually everyone who regularly uses computers is carrying a laptop around.
The one property of laptop computers that has trailed the other properties in improvement has been the period of time that the computer can be used under battery power that is directly related to ability to apply a recharge to the battery and the ability of the battery to retain a charge. It appears that the charge retentive time period that a laptop may be battery powered in use has been about two and at most four hours. This is too short for many airplane trips for example. The result has been the now classic example of dozens of business people or students trailing about in transportation terminals, public buildings and restaurants carrying along the one pound AC adapter and looking for an AC plug-in for their laptops. This, of course, makes the laptops a little less portable and convenient to use.
While the present invention does not eliminate AC adapter plug-in carrying or the need to recharge the portable computer battery, it offers an implementation that should extend the battery chargeablity and, consequently, the period of time on battery operation by about 25%. The present invention provides a system for a battery powerable portable computer with keyboard input that extends the battery charge lifetime during time periods when the computer is being operated in a battery powered mode comprising the combination of a battery providing power to the computer, a keyboard providing input to the computer through user keystrokes, apparatus operatively associated with each of a set of keys in the keyboard for converting the mechanical motion respectively applied to each of said set of keys during keystrokes to generate an electrical current, and an electrical connector for applying said electrical current to charge said battery. The apparatus for converting the mechanical motion to generate an electrical current should include at least one electrical generator.
In one desirable embodiment, this converting apparatus includes a set of electrical generators, each respectively associated with a corresponding one of said keys. In one application of this embodiment, each of the set of corresponding keys includes a magnetic key shaft movable during a keystroke; and the system further includes a plurality of conductive coils, each coil encircling a respective one of the magnetic key shafts whereby each magnetic shaft and encircling coil provides one of the set of electrical generators. In this connection, the set of keys with such associated current generation need not be all of the keys on the keyboard; a set of the most frequently used keys, such as most of the vowels and xe2x80x9cd, t, r, sxe2x80x9d may provide sufficient supplemental current for charging.
Also, piezoelectrical devices may be associated with each of a set of keys to convert the keystroke motions into electrical current.
In accordance with another embodiment of this invention, a single generator may be used. It would preferably be a small turbo-generator driven pneumatically or hydraulically by a fluid: gas or liquid cumulative stream driven by the cumulative motion of all of the set of keys. In one such embodiment, each of the set of keys includes a shaft piston movable during a keystroke to pneumatically drive a gas stream; and further includes a pneumatically driven turbo-generator and a conduit for pneumatically conducting the gas streams from each of the set of keys to drive said turbo-generator, whereby the electrical current is generated. In a similar embodiment, each of the set of keys includes a shaft piston movable during a keystroke to hydraulically drive a gas stream; and further includes a hydraulically driven turbo-generator, and a conduit for hydraulically conducting the gas streams from each of the set of keys to drive said turbo-generator whereby the electrical current is generated.
Also, with such fluid stream driven generators, the set of keys with such associated fluid driving pistons need not be all of the keys on the keyboard; a set of the most frequently used keys, such as most of the vowels and xe2x80x9cd, t, r, sxe2x80x9d may provide a sufficient stream of fluids to drive the turbo-generator to provide the current for charging.